My horse needs help jumping help me!!!!! please!!!?

Ok so my horse genie she is still learning to jump and she is doing really good. But she has this problem she is still learning about distance and height and she picks herback feet up really high and I fall foward because it's like she's bucking. Is there any excercise I can do. Also to help with her distance and height of jumps if there is another excercise. Thank you :-)